Light Rail Vehicle Noise: Evaluation of Rail Roughness and Noise from Wheel–Rail Interface

Author(s):  
Shankar Rajaram ◽  
Hugh Saurenman ◽  
Andrew Wong
Author(s):  
Ling-Kun Chen ◽  
Peng Liu ◽  
Li-Ming Zhu ◽  
Jing-Bo Ding ◽  
Yu-Lin Feng ◽  
...  

Near-fault (NF) earthquakes cause severe bridge damage, particularly urban bridges subjected to light rail transit (LRT), which could affect the safety of the light rail transit vehicle (“light rail vehicle” or “LRV” for short). Now when a variety of studies on the fault fracture effect on the working protection of LRVs are available for the study of cars subjected to far-reaching soil motion (FFGMs), further examination is appropriate. For the first time, this paper introduced the LRV derailment mechanism caused by pulse-type near-fault ground motions (NFGMs), suggesting the concept of pulse derailment. The effects of near-fault ground motions (NFGMs) are included in an available numerical process developed for the LRV analysis of the VBI system. A simplified iterative algorithm is proposed to assess the stability and nonlinear seismic response of an LRV-reinforced concrete (RC) viaduct (LRVBRCV) system to a long-period NFGMs using the dynamic substructure method (DSM). Furthermore, a computer simulation software was developed to compute the nonlinear seismic responses of the VBI system to pulse-type NFGMs, non-pulse-type NFGMs, and FFGMs named Dynamic Interaction Analysis for Light-Rail-Vehicle Bridge System (DIALRVBS). The nonlinear bridge seismic reaction determines the impact of pulses on lateral peak earth acceleration (Ap) and lateral peak land (Vp) ratios. The analysis results quantify the effects of pulse-type NFGMs seismic responses on the LRV operations' safety. In contrast with the pulse-type non-pulse NFGMs and FFGMs, this article's research shows that pulse-type NFGM derail trains primarily via the transverse velocity pulse effect. Hence, this study's results and the proposed method can improve the LRT bridges' seismic designs.


Author(s):  
Quan Gu ◽  
Jinghao Pan ◽  
Yongdou Liu

Consistent tangent stiffness plays a crucial role in delivering a quadratic rate of convergence when using Newton’s method in solving nonlinear equations of motion. In this paper, consistent tangent stiffness is derived for a three-dimensional (3D) wheel–rail interaction element (WRI element for short) originally developed by the authors and co-workers. The algorithm has been implemented in finite element (FE) software framework (OpenSees in this paper) and proven to be effective. Application examples of wheelset and light rail vehicle are provided to validate the consistent tangent stiffness. The quadratic convergence rate is verified. The speeds of calculation are compared between the use of consistent tangent stiffness and the tangent by perturbation method. The results demonstrate the improved computational efficiency of WRI element when consistent tangent stiffness is used.


1977 ◽  
Author(s):  
John M. Cord ◽  
Peter R. Norton

2008 ◽  
Vol 46 (11) ◽  
pp. 1061-1082 ◽  
Author(s):  
Yeon-Su Kim ◽  
Tae-Keon Lim ◽  
Sung-Hyuk Park ◽  
Rag-Gyo Jeong

2002 ◽  
Author(s):  
Wm. Murphy Madison ◽  
Jeffrey T. Lau

The focus of this paper is to study the application of Light Rail Vehicle (LRV) side-load requirements to Low Floor LRVs (LF LRVs). Although the side-load requirements of LRVs are not completely consistent among different transit authorities, an industry pseudo-standard of 40,000 lbs applied over an 8 foot span at the side sill has emerged. In LF LRVs, this standard may not provide the same level of safety as in High Floor LRVs (HF LRVs). In some US automobiles, the bottom of the bumper is higher than the top of the floor in LF LRVs. Given comparable sidewall construction, when a passenger vehicle impacts the side of an LRV, the opportunity for intrusion/override into the passenger compartment in a LF LRV is higher than that in a HF LRV. The popularity of light trucks, SUVs, minivans and other vehicles with high bumper heights further aggravates this situation.


Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2665 ◽  
Author(s):  
Han Zhang ◽  
Jibin Yang ◽  
Jiye Zhang ◽  
Pengyun Song ◽  
Xiaohui Xu

To coordinate multiple power sources properly, this paper presents an optimal control strategy for a fuel cell/battery/supercapacitor light rail vehicle. The proposed strategy, which uses the firefly algorithm to optimize the equivalent consumption minimization strategy, improves the drawback that the conventional equivalent consumption minimization strategy takes insufficient account of the global performance for the vehicle. Moreover, the strategy considers the difference between the two sets of optimized variables. The optimization objective is to minimize the daily operating cost of the vehicle, which includes the total fuel consumption, initial investment, and cycling costs of power sources. The selected case study is a 100% low-floor light rail vehicle. The advantages of the proposed strategy are investigated by comparison with the operating mode control, firefly algorithm-based operating mode control, and equivalent consumption minimization strategy. In contrast to other methods, the proposed strategy shows cost reductions of up to 39.62% (from operating mode control), 18.28% (from firefly algorithm-based operating mode control), and 13.81% (from equivalent consumption minimization strategy). In addition, the proposed strategy can reduce fuel consumption and increase the efficiency of the fuel cell system.


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